When New York's mayor, Michael Bloomberg, sent stormtrooper cops – equipped with batons, pepper spray and ear-splitting pain compliance devices – to sweep the Occupy protesters from Wall Street, he was attacked by the American TV commentator Keith Olbermann as "a smaller, more embarrassing version of the tinpot tyrants who have fallen around the globe this year".

That will have pricked Bloomberg's technocratic vanity, yet there he is, three months away from his 70th birthday and worth approximately $19.5bn, ordering his police chief, Ray Kelly, who has already hit 70 but is still, incidentally, a familiar figure on the Manhattan party circuit, to unleash a shocking level of force against young people who were simply agitating for a better economic system, more equity and transparency.

It is not a good look in a country where, as Joseph Stiglitz revealed in Vanity Fair, 1% of the population now takes nearly 25% of the nation's income. Justly or not, Bloomberg will be lumped with that international class of rich, often kleptomaniac, elderly men who have been brought down or who are looking shaky as demands for reform circle the world in what I believe to be a surge of optimism and, crucially, reason.

The Age of Downfalls, inaugurated when the 74-year-old President Ben Ali of Tunisia flew into exile and a coma, has claimed a surprising number of his generation. And it's not just the toppling of tyrants such as Ben Ali, the 83-year-old former President Mubarak of Egypt, or the 69-year-old Muammar Gaddafi, but also the demise of such men as Silvio Berlusconi (75), the former head of the IMF Dominique Strauss Khan (62) and the variety of threats faced by many Middle Eastern leaders, Rupert Murdoch (80) and the president of Fifa, Sepp Blatter (75).

Obviously, the same forces are not responsible for each man's troubles, but a year ago each of them seemed bombproof. We had no inkling that the world was about to be remade in such astonishingly short order; that history would decide, for whatever reason, that these men have had their time and the pathetic fiction of the dictator's hair dye would no longer work. If neutrinos can travel the length of Italy faster than the speed of light, calling into question our most fundamental assumptions about the universe, just about anything can happen.

One of the important traits of the Age of Downfalls is the exposure of myths and lies, a characteristic established in its initial months last winter by Wikileaks, which told us how things really were – that Saudi Arabia urged the US to bomb Iran; that the CIA tried to collect the UN general secretary's DNA; that China ordered the hacking of Google; that Ben Ali's family were looting Tunisia.

Much more has followed – a proper understanding of Greece's fraudulent application to join the euro; the revelations about oil companies owned by the Koch brothers paying for inaccurate and misleading information on climate change; the relentless uncovering of News International's evasions about hacking and police corruption; the protests when China started burying the wreckage of a train crash; and the exposure of the hopeful falsehood of the euro project, which suggests countries with widely varying economic performance and different cultures can unite in a single currency.

Whether through the market or the media, the internet or the instincts of the masses, truth has become the revolutionary weapon in the Age of Downfalls. That is surely a cause for optimism.

Indeed, the reason for hope is reason itself. Across the world, millions have demonstrated for fairness and enlightenment values. The chants of young people that echoed through the cities of Tunisia, Egypt, Libya, Yemen, Dubai, Syria, Greece, Spain, Italy, Israel, Chile, America and Britain are very similar – they are about freedom, self-determination, fairness, justice, access to education and jobs, as well as the corruption, mismanagement and greed of their elders.

In Burma, demand for reforms have led to Aung San Suu Kyi's announcement that she will stand in the next election. Even in Pakistan, a country generally regarded as beyond repair, Imran Khan's recent rally in Lahore struck the familiar notes of the Arab Spring. According to Tariq Ali in the London Review of Books, Khan's limited programme to end corruption, institute a strict tax regime, restore public services and terminate the servile relationship with the US was cheered as loudly by "young women in jeans and T-shirts… as those in hijabs". It is now possible to believe that Khan and Suu Kyi may both end up bringing a very different eye to the government of their peoples.

Reason has not won the battle against mythomaniac religions and greedy interests, particularly with the right of American politics, which embraces both these menaces as an article of national pride. Yet something deep and impressive is going on in the new generation, who have come of age. it seems. with an almost innate understanding of justice and fairness, and are – significantly – managing their religious convictions in the context of wanting improved societies.

Barely a week has gone by this year when I have not thrilled at the turn of events and pinched myself at some new surprise. A small example is the latest crime survey for the US, released by the FBI in the summer. Murder, rape, robbery and other serious crimes have fallen to a 48-year low. The murder rate has halved and robberies are down 10%, following an 8% fall in 2009. Canada shows the same fall (without locking up the vast numbers the US has) and England and Wales recorded an overall drop of 4%, with violence causing injury and firearms offences both down by 9%. We are perhaps better than we know, or at least better than governments give us credit for.

The key question seems to be this: will all the hopes of the year evaporate as we revert to type? Are we basically limited by human nature? Recent Swiss research published by the New Scientist suggests that each of us is programmed to behave like Ben Ali or Putin, or the corporate monsters, Berlusconi and Murdoch. If a person is given power over people and has more to gain from underhand dealings, abuse almost always follows. Yet research shows that a very few individuals will defy the pattern and set an example and that culture and institutions restrict corruption and the abuse of power.

That is the vital point: millions are calling not just for fairness and justice, but a reform of the institutions that will guard against the crimes and corruption of the few against the many. This is an amazingly important step for humanity and it is one of the reasons that despite the sense of impending crisis, I take heart from the Age of Downfalls.